Group emergency call systems are intended for use by volunteer fire personnel, civil defense, or other groups requiring quick and simultaneous distribution of a message from a single individual to a number of other individuals. This service has historically been used in rural areas to provide one-way communication from a control position to a reselected group or groups of individuals. The traditional method of providing this service has been to install an adjunct switching system in the central office exchange that is cross-connected to lines dedicated for emergency use by the group emergency call system. Examples of such prior art cross-connected adjunct or add-on systems are the 291 Emergency Reporting System by Tellabs Inc., and the Emergency Out Dial System manufactured by Message Processing System, Inc. Such prior art systems suffer from the disadvantages of being expensive and complex, and requiring external maintenance terminals and sophisticated electronic equipment. Furthermore, such add-on emergency group call systems are incapable of providing standard central office or PBX call functions such as automatic call forwarding from an emergency hunt group subscriber set to a further set in the exchange. For example, the aforementioned 291 Emergency Reporting System utilizes a siren for notifying subscribers whose sets have been placed in call forward or do-not-disturb modes as well as rural areas and small towns who have been devastated in recent years by severe weather conditions.
Communicating messages by telephone has increased tremendously in the past decade. Communicating information such as advertisements and public announcements has become very important. Leaving pre-recorded messages to subscribers has become a popular technique for communicating information to thousands of individuals and businesses. There have many problems associated with leaving pre-recorded messages. For example, many pre-recorded messages are not noted immediately because the recipients do not quickly respond to the pre-recorded message and/or the pre-recorded messages are not correctly received by the answering machines. Thus, it has become more popular than ever in the communicating of messages to use computers, which will detect conditions that an answering machine is receiving the call.
Attempts have been made over the years to overcome the problems with delivering messages to telephone answering machines. See for example U.S. Pat. Nos. 4,667,065 to Bangerter; 4,941,168 to Kelly, Jr.; 5,371,787 to Hamilton; 5,430,792 to Jesurum et al.; and 5,581,602 to Szlam et al. However, these patents are generally limited to sensing audio signals generated by the answering machines and do not cover all the types of answering machines which start recording after different selected delay times. For example, many of these devices commence playing a recorded message based on mistakenly detecting when the “beep” has occurred. The false “beep” signal is a common problem for real callers trving to leave messages on answering machines. Furthermore, these patents do not fully analyze the connected calls in order to utilize preselected delay times to deliver and fully play recorded messages which is of vital importance when delivering emergency messages warning of the approach of severe weather conditions which can endanger human life.
Message delivery systems, which deliver a recorded message to an answering machine, must solve the problem of determining when to “Launch” (begin playback of) the prerecorded message. Conventional systems rely on a timer to determine the moment to begin playback of the recorded message which systems experience a high percentage of truncation of the recorded message. Other serious problems includes: the called answering machine may disconnect the call due to prolonged silence before the message playback begins; failure to listen to the message since pre-recorded messages oftentimes do not personally address the individuals being called; and generally ignoring important messages such as when the message is dealing with imminent dangerous weather conditions and other imminent dangers, and the like.
Other patents of general message communication interest include, U.S. Pat. Nos. 5,404,400 to Hamilton; 5,444,767 to Goetcheus et al.; 5,652,784 to Blen et al.; and 5,787,151 to Nakatsu et al. However, none of these patents solve all of the above problems.
Although the above has dealt with the problems relating to pre-recorded messages introduced onto an answering machine, it is further essential that a severe weather warning of imminent danger to area where the intended recipient is present and/or has an interest in monitoring be provided. There have been extensive efforts by the United States National Weather Service to warn of emergency weather conditions. The National Weather Service broadcasts weather and weather emergencies across the United States using seven different regional weather channels. These seven channels range in frequency from 162.4 to 162.55 MHz and employ narrow band FM modulation. When a regional weather emergency exists, the weather service modulates a 1050 Hz tone on the appropriate 162 MHz weather frequencies for 10 seconds to alert the public of an impending weather emergency. However, the 1050 Hz tone will not be heard by anyone who is not listening to a radio tuned to that local weather channel at 162 MHz, at the time of the emergency. Additionally, individuals will only be warned of weather events occurring within their immediate signal broadcast range. If an individual needed to be alerted to severe weather events taking place hundreds of miles away, for example individuals with elderly relatives in a distant city or a person monitoring the conditions at a distant ranch containing livestock, the National Weather Service broadcasts in those areas would not reach their location, and therefore no warning would be communicated.
One approach to this non-reception problem is to implements a weather radio receiver into a cordless telephone system to allow a user to hear the National Weather Service broadcast over the cordless telephone. A control allows the user to listen to the regional weather broadcast either from the base unit or from the handset unit. When a weather emergency exists, a 1050 Hz tone transmitted by the weather service will be announced through the base unit speaker as well as through the handset unit speaker regardless of whether the user is listening to the regional weather broadcast or is on the telephone at the time of the emergency (see U.S. Pat. No. 5,541,980)
There still represents a serious need to provide a rapid response system to directly alert one who is interested in protecting the lives of oneself, oneself and property from threatening severe weather conditions such as tornadoes, hurricanes, lightning, hailstorms flash floods and windstorms by a warning system which delivers a severe storm warning alertly to the personal telephone or other communication system which can protect life and/or property for 24 hours a day.